A few years ago, filmmakers trying to capture the vanishing beauty of ocean reefs took on an epic project. They would do underwater filming in digital 3D, often trekking to extremely remote locations to bring you insanely gorgeous visuals of subterranean worlds currently threatened by ocean acidification. That's why they made The Last Reef — to document the marvelous diversity of nature, and issue a clarion call to those of us who want to preserve it as much as possible.

We've got an exclusive, behind-the-scenes video for you of how the team filmed a rare species of stingless jellyfish in Jellyfish Lake.

Here's the movie synopsis:

Fly across iridescent tropical reefs, brush through a cloud of a million jellyfish, visit an alien world where the closer you look, the more you see, where the tiniest creatures support the greatest predators…

We think of reefs as exotic, distant places with little or no connection to our everyday world. Yet every reef is a living city beneath the sea with a parallel existence to ours, distant yet undeniably connected.

Reefs are hotspots of biodiversity as vital to life on earth as the rain-forests. They have been shaping our shorelines, literally forming islands and mountains, for millions of years.

The fossil record shows that given time they have recovered from all of earth's major extinction events.

Even reefs pulverised by atomic blasts at Bikini Atoll have regenerated.

Yet within our lifetime reefs have come to face their greatest threat…[ocean acidification].

Find out more about The Last Reef, including where to see it in your area, on the official film website.